• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.225-230
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• 1998

In this paper, we introduce the concepts of intuitionistic fuzzy points and intuitionistic fuzzy neighborhoods. We investigate properties of continuous, open and closed maps in the intuitionistic fuzzy topological spaces, and show that the category of Chang's fuzzy topological spaces is a bireflective full subcategory of that of intuitionistic fuzzy topogical spaces.

• 충청수학회지
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• 제15권1호
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• pp.7-23
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• 2002

We introduce the notion of expansivity for a continuous surjection on a compact metric space, as the positively and negatively expansive map. We also prove that some well-known properties about positively expansive maps in [2] hold by using our definition.

• 대한수학회논문집
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• 제35권4호
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• pp.1309-1318
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• 2020

In this paper we extend the concept of topological stability from continuous maps to the corresponding induced maps and prove that a continuous map is topologically stable if and only if its induced map also is topologically stable.

• 충청수학회지
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• 제31권4호
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• pp.461-466
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• 2018

$Let\;f:X{\rightarrow}X$ be a continuous surjection of a compact metric space X and let ${\sigma}_f:X_f{\rightarrow}X_f$ be the shift map on the inverse limit space $X_f$ constructed by f. We show that if a continuous surjective map f has some shadowing properties: the asymptotic average shadowing property, the average shadowing property, the two side limit shadowing property, then ${\sigma}_f$ also has the same properties.

• Spatial Information Research
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• 제15권2호
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• pp.95-109
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• 2007

최근 도로네트워크 환경에서 위치기반 서비스를 제공하는데 있어서 2차원 공간 데이터를 기반으로 하고 있다. 3차원 데이터는 사용자에게 2차원 보다 친근감을 주는 중요한 매체가 되지만, 데이터의 크기가 커지기 때문에 이동단말기의 메모리 공간의 한계로 모든 데이터를 저장할 수 없게 되는 문제점이 발생한다. 본 논문에서는 도로네트워크에서 이동객체에게 3차원 데이터를 제공할 수 있는 연속원근질의를 정의하고 이를 처리하는 방법론을 제안하였다.

• 대한수학회지
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• 제46권2호
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• pp.225-236
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• 2009

The equicontinuity and scattering properties of continuous semi-flows are studied on a compact metric space. The main results are obtained as follows: first, the complexity function defined by the spanning set is bounded if and only if the system is equicontinuous; secondly, if a continuous semi-flow is topologically weak mixing, then it is pointwise scattering; thirdly, several equivalent conditions for the time-one map of a continuous semi-flow to be scattering are presented; Finally, for a minimal continuous map it is shown that the "non-dense" requirement is unnecessary in the definition of scattering by using open covers.

• 대한기계학회논문집A
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• 제25권11호
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• pp.1759-1766
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• 2001

Vibration transient generated by developing localized fault in gear can be used as indicators in gear fault detection. In this paper, we propose the zoomed phase map for a fault signal using continuous wavelet transfers to detect this vibration transient. Local fault induces the abrupt fluctuation of load exciting tooth and phase lag in the vibration signal measured on the gearbox. The relatively large fault like "tip breakage" easily can be detected by the clear fluctuation of exciting load. However, minor fault like "initial pitting"cannot be detected using the load fluctuation. To defect this kind of minor fault, the phase map for a fault signal is taken into account. The phase lag by minor fault is observed well in the zoomed phase map.

• Journal of applied mathematics & informatics
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• 제14권1_2호
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• pp.277-288
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• 2004

In this paper, we discuss a continuous self-map of an interval and the existence of an uncountable strongly chaotic set. It is proved that if a continuous self-map of an interval has positive topological entropy, then it has an uncountable strongly chaotic set in which each point is recurrent, but is not almost periodic.

• East Asian mathematical journal
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• 제27권3호
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• pp.373-380
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• 2011

In this paper L-fuzzy ${\omega}$-closed and L-fuzzy ${\omega}$-open sets are introduced. Also a new class of L-fuzzy topological space called L-fuzzy ${\omega}$-basically disconnected space is introduced. Several characterizations and some interesting properties are also given.

• 호남수학학술지
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• 제35권2호
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• pp.319-327
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• 2013

In this paper we compare the notion of proper map in the category of topological spaces with that in the category of semialgebraic sets. To do this, we find some equivalence conditions for semialgebraically proper maps. In particular, we prove that a continuous semialgebraic map is semialgebraically proper if and only if it is proper. Moreover, we compare the semialgebraically proper map with the proper map in the sense of Delfs and Knebush [4].